1. Field of the Invention
The invention relates to a tape cassette which can be detachably installed in a printing device having a printing head and a platen that opposes the tape cassette and parted therefrom relatively, and more particularly, to the tape cassette whose tape has a desired heat transfer image thereon to be thermally transferred onto an image receiving member such as cloth, paper and so on.
2. Description of Related Art
In a printing device in which this type of tape cassette is loaded, a rotatable character selection dial 4 is provided on top of a main body 2 as shown in FIG. 4. Function keys 10, such as a power supply switch 6 and a print key 8, which are operable for controlling the printing device 1, and a crystal display 12 (LCD), for displaying input characters, symbols and the like, are provided adjacent to the character selection dial 4. A cassette receiving accommodation recess 80 is provided on the back side of the main body 2 as shown in FIG. 5. A tape cassette 70 can be detachably loaded therein.
A printing spool 18 is rotatably disposed in the tape cassette 70 as shown in FIG. 8. A printing tape 20, which is comprised of a substrate sheet 20b and a hot-melting type adhesive layer 20a (see FIG. 9) and is for being thermally transferred with pressure onto a cloth, is wound on the printing spool 18 with the hot-melting type adhesive layer 20a on the inner side.
The materials, structure and features of the hot-melting type adhesive layer 20a and the substrate sheet 20b are same as those disclosed in Japanese Laid Open No. 3-292187.
The hot-melting type adhesive layer 20a is transferred onto a cloth with characters and symbols printed on the hot-melting type adhesive layer 20a by applying heat and pressure to the printing tape 20 by an iron or similar device. Therefore, the hot-melting type adhesive layer 20a must be easily separable from the substrate sheet 20b regardless of the hot or cool state of the hot-melting type adhesive layer 20a after the layer 20a is transferred onto the cloth. That is, the substrate sheet 20b must be separable from the hot-melting type adhesive layer 20a just after the transfer or adhesion of the hot-melting type adhesive layer 20a to the cloth using heat and pressure and even after a long time has passed following the transfer or adhesion. In this respect, the hot-melting type adhesive layer 20a is bonded to the substrate sheet 20b by an adhesive with a releasable or separable property.
Because characters, symbols, etc. are printed on the hot-melting type adhesive layer 20a by the printing device 1, the hot-melting type adhesive layer 20a must be formed of a material which provides an ink-philic property to ensure a high quality of printing without blur, blotting, distortion and/or other substandard print characteristics.
Furthermore, the hot-melting type adhesive material must be selected in due consideration of factors which may affect the quality of the finally transferred print image after heating and pressing. These factors include brilliance and fastness against washing, light and sweat. According to these factors, thermoplastic resin is used for the hot melt adhesive.
Release processing is provided to the substrate sheet 20b to prevent blocking or bonding of the hot-melting type adhesive layer 20a thereto.
An ink ribbon 26 which is obtained by coating a heat melting ink over a base film is wound on a ribbon supplying spool 28 with its ink surface on the inner side and the ink ribbon 26 is wound on a winding up spool 30 after printing.
The printing tape 20 is fed to a roller entrance 34 via the printing tape spool 18 and a guide shaft 32. Then, from a tape feeding roller 36, the printing tape 20 is fed outside the tape cassette 70 through a slit below a tape presser 23.
On the other hand, the ink ribbon 26 is fed from the ribbon supplying spool 28, between the printing tape 20 and the guide shaft 32, and then to the roller entrance 34 in overlapping contact with the printing tape 20. After the ink ribbon 26, overlapped with the printing tape 20, is fed to the roller entrance 34, the ink ribbon 26 changes its rotating direction, by 180 degrees, by means of a releasing plate and is fed to a ribbon winding up spool 30. A releasing plate 40 is fixed in the tape cassette 70 at a position which is away from a heat-generating element 49 of a thermal head 48, by a predetermined distance, downstream of the ink ribbon 26 feeding direction. The releasing plate 40 releases the ink ribbon 26 from the printing tape 20.
A thermal head insertion recess 47, which is surrounded by the ink ribbon 26 and a surrounding wall 46 is provided upstream of the releasing plate 40 in the feeding direction. The thermal head 48, installed in the main body 2, is inserted into the insertion recess 47 when the tape cassette 70 is loaded in the printing device 1. The heat-generating element 49 is arranged in a row at one end of the thermal head 48 so that the heat-generating element is at a right angle to the ink ribbon 26 feeding direction thus the heat-generating element 49 faces the ink feeding ribbon.
As shown in FIG. 5, a tape feeding drive shaft 50 and a ribbon winding up spool shaft 52 are installed in the main body 2. The tape feeding drive shaft 50 is engaged to the tape feeding roller 36 and the ribbon winding up spool shaft 52 is engaged to the ribbon winding up spool 30 when the tape cassette 70 is loaded in the cassette recess 80. The tape feeding drive shaft 50 and the ribbon winding up spool shaft 52 are driven by a pulse motor.
A movable platen roller 58 and a drive roller 60 are rotatably supported on a roller holder 56 which is rotatably supported by a rotation shaft 54 fixed to the main body 2 of the printing device. The movable platen roller 58 and the drive roller 60 are inserted into the roller entrance 34 by the operation of a roller release lever 62 that rotates the roller holder 56 around the rotation shaft 54. When the movable platen roller 58 and the drive roller 60 are inserted into the roller entrance 34, the printing tape 20 and the ink ribbon 26, exposed to the roller entrance 34, are sandwiched between the movable platen roller 58 and the heat-generating elements 49 while being overlapped with one another. Downstream of the ink ribbon 26 feeding direction, the printing tape 20 is fed outside the tape cassette 70 sandwiched between the driving roller 60 and the tape feeding roller 36.
A cutting lever 64 and a rotation cutter 66, which rotates in accordance with a rotation of the cutting lever 64, are provided downstream of the driving roller 60 of the main body 2. A cutting blade receiving unit 81, consisting a flat surface for receiving a cutting blade 66a of the rotation cutter 66 is disposed in the tape cassette 70 as shown in FIG. 9. A groove 81a, having a "V" shape is formed in the cutting blade receiving unit 81 by cutting the printing tape 20.
The tape cassette, having the above-mentioned structure, operates as described below.
A tape cassette 70 is loaded into the printing device 1. Desired characters and symbols can then be input, using the character selection dial 4 and the function keys 10, by an operator.
If the print key 8 is pressed by the operator, the thermal head 48 is energized and the heat-generating element 49 generates heat based on data defining the input characters and symbols simultaneously with the feeding, at a predetermined speed, of the overlapped printing tape 20 and the ink ribbon 26. As a result, an ink layer 21, consisting of ink images of the input characters and symbols is formed on the hot-melting type adhesive layer 20a of the printing tape 20, and the printing tape 20 is fed to the outside of the printing device 1 by the driving roller 60.
After printing is complete, the cutting lever 64 is rotated by the operator, in the direction of the arrow A shown in FIG. 8, and the rotating cutter 66 rotates in the direction of the arrow B. As a result, the printing tape 20 fed outside the cassette 70 is pressed against the cutting blade receiving unit 81 of the tape cassette 70 by the cutting blade 66a of the rotation cutter 66 and the printing tape 20 is cut.
The cut printing tape 20 is then placed on a cloth with the ink layer 21 against the cloth. Heat and pressure are applied from the substrate sheet 20b side by an iron or the like and the hot-melting type adhesive layer 20a is transferred onto the cloth with the ink layer 21 of the characters and symbols previously formed on the printing tape 20. Thus, images of the characters and symbols are formed on the cloth with the hot-melting type adhesive layer 20a by releasing the substrate sheet 20b from the hot-melting type adhesive layer 20a after the hot-melting type adhesive layer 20a is transferred to the cloth by the iron.
In the above-mentioned tape cassette, there is a problem. As mentioned above, the hot-melting type adhesive layer 20a of the printing tape 20 and the substrate sheet 20b are bonded together by a releasable or separable adhesive and the release processing is provided to the substrate sheet 20b. However, to cut the printing tape 20, it is pressed into the groove 81a formed in the cutting blade receiving unit 81 of the tape cassette 70, by the cutting blade 66a of the rotation cutter 66 as shown in FIG. 9.
Therefore, the pressure of the cutting blade 66a causes the hot-melting type adhesive layer 20a, on which the characters and symbols are printed, to be separated from the substrate sheet 20b and enter the groove 81a. As a result, the hot-melting type adhesive layer 20a might not be completely cut. Therefore, the printing tape 20 has not been completely cut.
Further, the images of the characters and symbols printed on the printing tape 20 are exposed until they are transferred onto a cloth by applying heat and pressure. Therefore, if the operator touches the images printed on the printing tape 20 before the printing tape 20 is pressed and heated onto the cloth by an iron, the ink on the printing tape 20 might be released from the printing tape 20 and a complete transfer of the images to the cloth cannot be obtained.